1. Was he heading towards the kitchen? They go to the kitchen, get some meat, grill it, and eat it - I'm not sure how much it does for their hunger levels.
2. My kitty will sit by the bowls and meow until I feed her sometimes. If your dog does something like that, you'll know it's time to refill the bowls, or you can just refill it periodically and he/she will go and eat. I don't think they can starve or anything, but I'm not sure.
3. I don't think so. I tried renaming a VV3 game once, and I lost the tribe. I don't know if it's the same in VF2, but I think renaming it forces you to start over.